The present invention relates to an optical connector for use in optical communications. The optical connector of the invention is mounted in a vehicle for use in optical communications inside the vehicle, or is used in optical communications such as an FA (Factory Automation), a home LAN (Local Area Network), an audio and a PC (Personal Computer), for example.
Recently, the computerization of vehicles has been developing dramatically. For example, displaying a vehicle location on a map using a car navigation system and management for solving traffic congestion or the like utilizing the ITS (Intelligent Transport Systems) are conducted. With such computerization, communication information throughput such as data, image and voice in vehicles has been increasing. As high-capacity information transmitting media, optical fibers have been used.
When information is transmitted by using the optical fiber, at the present moment, a transmitted signal is converted from an electric signal to a light signal by an E/O (electric/optical) conversion device and the light signal is transmitted to the receiving side through the optical fiber. On the receiving side, the light signal transmitted through the optical fiber is converted to an electric signal by an O/E (light/electric) conversion device for extraction. By this electric signal, a desired signal processing such as control is applied.
Accordingly, when information transmission is conducted by using the optical fiber, it is needed that the E/O conversion device is connected to a transmitting optical fiber and an optical fiber where light signals are transmitted is connected to the O/E conversion device. As one example of a method for connecting an optical fiber to an optical device such as an E/O conversion device or O/E conversion device, a connecting method using an optical connector is proposed.
FIGS. 7A and 7B schematically depict sections illustrating one example of the method for connecting an optical fiber to an optical device using the aforesaid optical connector. The connecting method shown in these drawings is a connecting method where a connector (plug connector) 2 is detachably connected to an adaptor (receptacle connector) 1. To the adaptor 1, an optical device such as an E/O conversion device or O/E conversion device (not shown) is connected. To the optical connector 2, an optical fiber 18 is fixed.
As shown in FIGS. 7A and 7B, the adaptor 1 has a box-like receptacle housing 3 having a connector insertion part 10. An end part opening of the connector insertion part 10 is formed to be an insertion opening 12 for the optical connector. The top of the connector insertion part 10 is formed with a pawl fitting hole 11 as a locking part for the optical connector. Additionally, to the opposite side of the insertion opening 12 for the optical connector, an optical device such as an E/O conversion device or O/E conversion device, not shown, is connected.
On one hand, the optical connector 2 has a box-like plug housing 6. To an optical fiber fixing part (not shown) formed in the plug housing 6, the connection end face side of the optical fiber 18 is inserted and fixed. The upper face 7 side of the plug housing 6 is formed with an arm supporting part 17 standing from the front end 20 side of the plug housing 6 upward. A lock arm 5 is formed to extend from the arm supporting part 17 to the back end 21 side of the plug housing 6.
The lock arm 5 is spaced from an upper face 7 of the plug housing 6. The lock arm 5 is formed with a locking pawl 4 for fitting in the pawl fitting hole 11 of the adapter 1, the locking pawl 4 is formed to extend upward. The locking pawl 4 has a slope 14 that is formed to be higher as it goes to the back end side.
When the optical connector 2 is moved in the direction of an arrow A in FIG. 7A and is inserted into the optical connector insertion part 10 of the adapter 1, the locking pawl 4 of the optical connector 2 is fit in the pawl fitting hole 11 of the adapter 1, as shown in FIG. 7B. By this fitting, the optical connector 2 is in a state that it is prevented from falling off from the adapter 1. Additionally, the back end 21 side of the plug housing 6 and the end side 15 of the lock arm 5 are in a state of extending from the connector insertion opening 12 of the adapter 1.
Then, as shown in broken lines shown in FIG. 7B, when the end side 15 of the lock arm 5 is drawn to the upper face 7 side of the plug housing 6, the lock arm 5 comes close to the upper face 7 of the plug housing 6 as the base end thereof is used as a supporting point. Then, the locking pawl 4 is moved to the plug housing 6 side through a track indicated by an arrow B. This movement unlocks the locking pawl 4 from the pawl fitting hole 11 of the adapter 1. Then, when the optical connector 2 is pulled in the direction of an arrow C in this state, the optical connector 2 is removed from the adapter 1.
Furthermore, in the configuration shown in FIGS. 7A and 7B, the track of the locking pawl 4 indicated by the arrow B needs to be ensured when the end side 15 of the lock arm 5 is drawn to the upper face 7 side of the plug housing 6. That is, in the configuration described above, it is necessary to prevent the back end side of the locking pawl 4 from being caught by the wall surface of the pawl fitting hole 11. To this end, a length L2 of the pawl fitting hole 11 shown in FIG. 7A is formed longer than a length L1 of the locking pawl 4. By this length setting, when the optical connector 2 is fit to the adapter 1, a space R about 0.3 mm, for example, is formed between the pawl fitting hole 11 and the back end part of the locking pawl 4, as shown in FIG. 7B.
Meanwhile, the connection accuracy of the optical fiber 18 to the optical device using the above-described optical connector 2 is determined by a relative position of the optical connector 2 and the adapter 2 in the state of the optical connector 2 being fit to the adapter 1.
However, in the configuration shown in FIGS. 7A and 7B, when the optical connector 2 is fit to the adapter 1, the space R is formed between the pawl fitting hole 11 and the back end part of the locking pawl 4 and a play by the amount of the space R is generated. On this account, the connection of the optical fiber 18 to the optical device using the aforementioned connecting method has had a problem that generates a connection loss of the optical fiber 18 to the optical device due to the play by the amount of the space R.
Then, in order to solve this problem, a method has been proposed that the optical fiber 18 is connected to the optical device by connecting an optical connector 2 having a configuration different from the aforesaid optical connector 2 to the adapter 1. The optical connector 2 in the proposal has a configuration shown in FIGS. 8A and 8B. As shown in these drawings, the configuration of the adapter 1 connected to the optical connecter 2 is the same as FIGS. 7A and 7B and thus the description thereof is omitted.
The optical connecter 2 shown in FIGS. 8A and 8B has a plug housing 6 where an optical fiber 18 is inserted and fit as similar to the optical connector 2 shown in FIGS. 7A and 7B. However, an upper face 7 of the plug housing 6 is formed with an arm supporting part 17 standing from the back end 21 side thereof to the upper side. A lock arm 5 is formed to extend from the arm supporting part 17 toward the front end 20 side of the plug housing 6. The lock arm 5 is spaced from the upper face 7 of the plug housing 6. At the front end of the lock arm 5, a locking pawl 4 is formed as similar to the optical connector 2 shown in FIGS. 7A and 7B.
Fitting the proposed optical connector 2 to an adapter 1 is conducted by the movement of the optical connector 2 in the direction of an arrow A, as shown in FIG. 8A. By this movement, insertion and fitting to a connecter insertion part 10 and fitting the locking pawl 4 of the optical connector 2 to a pawl fitting hole 11, as shown in FIG. 8B, are conducted.
On the other hand, when the optical connector 2 is removed from the adapter 1, it is conducted by pushing a base end side 25 of the lock arm 5 toward the upper face 7 side of the plug housing 6, as indicated by an arrow Bxe2x80x2 shown in FIG. 8B. By this operation, the lock arm 5 is brought close to the upper face 7 side of the plug housing 6 as the base end part is used as a supporting point, as indicated by broken lines shown in the drawing. Then, the locking pawl 4 is moved to the plug housing 6 side through the track indicated by an arrow B and is removed from the pawl fitting hole 11 of the adapter 1. When the optical connector 2 is pulled in the direction of an arrow in this state, the optical connector 2 is removed from the adapter 1.
In FIGS. 8A and 8B, when the base end side 25 of the lock arm 5 is pushed toward the upper face 7 side of the plug housing 6, the locking pawl 4 of the optical connector 2 is moved through the track indicated by the arrow B shown in FIG. 8B. On this account, the locking pawl 4 is not caught by the inner wall of the pawl fitting hole 11. Thus, in the configuration shown in FIGS. 8A and 8B, a length L1 of the locking pawl 4 and a length L2 of the pawl fitting hole 11 are formed to be almost equal.
Accordingly, the configuration shown in FIGS. 8A and 8B can solve the problem due to the play by the amount of the space R between the locking pawl 4 and the pawl fitting hole 11 in fitting the optical connector 2 to the adapter 1 as shown in FIGS. 7A and 7B.
However, in the optical connector 2 shown in FIGS. 8A and 8B, when the optical connector 2 is removed from the adapter 1, the base end side 25 of the lock arm 5 is pushed toward the upper face 7 side of the plug housing 6 and the locking pawl 4 is removed from the pawl fitting hole 11. Then, the length of the lock arm 5 needs to be longer so that the base end side 25 of the lock arm 5 is pushed by a human finger, for example, to tilt the lock arm 5. Accordingly, in the configuration shown in FIGS. 8A and 8B, a problem has arisen that the plug housing 6 of the optical connector 2 needs to be formed longer, which causes an increase of the optical connector 2 in size.
An optical connector of the invention comprising:
a housing;
bridge supporting parts disposed at a back end side of an upper face of the housing and standing from both sides of the upper face of the housing;
a bridge part spaced from the upper face of the housing as supported at both sides thereof by the bridge supporting parts;
a lock arm formed in a midway part of the bridge part and extended toward a front end side of the housing;
a locking pawl extended upward at a position of a front end side of the lock arm for locking into a locking part of a connecting counter part side in inserting and fitting the optical connector to the connecting counter part side.
Additionally, in one embodiment of the invention, the front end side of the lock arm is extended longer than a locking pawl forming part and the front end thereof is fixed to the upper face of the housing.
In the invention of the aforesaid configuration, in the midway part of the bridge part formed on the back end side of the upper face of the housing, the lock arm having the locking pawl on the front end side thereof is formed to extend toward the front end side of the housing. On this account, when the optical connector is inserted into the connecting counter part side from the front end side thereof, the aforesaid locking pawl locks into the locking part of the connecting counter part side in inserting and fitting the optical connector to be a state of preventing falling off.
Additionally, the aforesaid bridge part is spaced from the upper face of the housing as supported at both end sides thereof by the bridge supporting parts standing from both sides of the upper face of the housing. On this account, when the midway part of the bridge part is pushed from the upper side, the bridge part is elastically deformed as the bridge supporting parts are used as supporting points and the midway part of the bridge part comes close to the upper face of the housing. Then, the aforesaid lock arm comes close to the upper face of the housing along with the bridge part and the locking pawl formed at the front end side of the lock arm is removed from the locking part of the connecting counterpart side. When the housing is pulled toward the back end side in this state, the optical connector is removed from the connecting counter part side.
That is, the invention is the configuration where the locking pawl at the lock arm front end side is brought close to the upper face of the housing, using the bridge supporting parts standing from the both sides of the upper face of the housing on the back end side of the housing as the supporting points. Therefore, even though the width of the bridge part (a length in the direction of inserting the optical connector) is short, the locking pawl can be brought close to the upper face of the housing, and the length of the lock arm or housing does not need to be formed longer in the direction of inserting the optical connector. Thus, a small-sized optical connector can be realized.
Furthermore, in the invention, the lock arm is brought close to the upper face of the housing using the bridge supporting parts at the back end side of the housing as the supporting points. Therefore, it is not necessary to form a space between the locking pawl and the locking part (a hole for fitting the lick pawl, for example) of the connecting counter part side. Accordingly, it can be prevented that the space creates a play to generate a connection loss between the optical device and the optical fiber to be inserted into the optical connector.
Moreover, the optical connector where the front end side of the lock arm is extended longer than the locking pawl forming part and the front end thereof is fixed to the upper face of the housing can realize an optical connector having higher reliability. The reason is that the optical fiber inserted into the optical connector or electrical wiring disposed around the optical connector can be prevented from entering the under side of the lock arm in the optical connector having the configuration.